Place caps on the end of a Boomwhacker tube to lower the tone by a full octave</br>Comes in a set of 8</br>Play the tubes as usual or hold them vertically and tap on the floor as a stamping tube</br>Combination of Boomwhackers allows for a 3-octave range</br>Place on the higher-octave Boomwhacker tubes to create the same tones as the bass octave tubes</br></br>Product Description</br></br>The Caps lower the tone of the Tubes by an octave. The 8 Pack contains enough caps to use on any of our Boom whackers Sets.</br><br/>http://www.amazon.com/gp/product/B00004TT3S